package _搜索;

import java.util.Arrays;
import java.util.Scanner;

// 斐波那契数列第n个数的值
public class _04DFS回忆 {
	static long dp[];
	static long mod = (long)1e9 + 7;
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int n = scan.nextInt();
		dp = new long[n + 1];
		Arrays.fill(dp, -1);
		dp[1] = 1;
		dp[2] = 1;
		System.out.println(dfs(n));
		scan.close();
	}
	public static long dfs(int n) {
		
		if(dp[n] != -1) {
			return dp[n];
		}
		
		long ans = dfs(n-1) + dfs(n-2);
		ans %= mod;
		dp[n] = ans;
		
		return dp[n];
	}
}
